Strings. Valid Palindrome.

Author: FedorovAlexander

README.md

@@ -18,3 +18,4 @@
 2. [Reverse Integer](./Strings/reverse-integer.js)
 3. [First Unique Character in a String](./Strings/first-unique-character-in-a-string.js)
 4. [Valid Anagram](./Strings/valid-anagram.js)
+5. [Valid Palindrome](./Strings/valid-palindrome.js)

Strings/valid-palindrome.js

@@ -0,0 +1,38 @@
+// Задача на leetcode: https://leetcode.com/explore/interview/card/top-interview-questions-easy/127/strings/883/
+
+//Способ 1:
+
+var isPalindrome = function (s) {
+	const string = s.replace(/[^0-9a-z]/gi, "").toLowerCase();
+	const reverseString = s
+		.replace(/[^0-9a-z]/gi, "")
+		.toLowerCase()
+		.split("")
+		.reverse()
+		.join("");
+
+	if (string === reverseString) {
+		return true;
+	}
+
+	return false;
+};
+
+//Способ 2:
+
+var isPalindrome2 = function (s) {
+	const string = s.replace(/[^0-9a-z]/gi, "").toLowerCase();
+
+	let left = 0;
+	let right = string.length - 1;
+
+	while (left < right) {
+		if (string[left] !== string[right]) {
+			return false;
+		} else {
+			left++;
+			right--;
+		}
+	}
+	return true;
+};